The effects of monaural and binaural tonal stimulation on the discharge pattern of single units located lateral to the medial superior olive of the superior olivary complex of the cat are under investigation. The superior olivary complex is composed of third order neurons in the auditory pathway of the cat. Insulated, gold plated stainless steel microelectrodes with platinum black tips are inserted ventrally into the brainstem of barbiturate anesthetized cats. The responses of single neurons are recorded extracellularly. Following an experiment electrode tip positions are determined histologically by use of the Prussian Blue reaction. A buffered digital magnetic tape recorder and on-site disc operating computer system will be used to investigate the discharge patterns of S- segment neurons to monaural pure tone stimulation, to monaural two-tone stimulation, and to binaural stimulation with pure tones. It is the purpose of this investigation: (1) to characterize the discharge pattern of SOC neurons with as few measures as possible; (2) to determine if any of these measures characterizing the discharge patterns are related to stimulus parameters; and (3) to determine and describe the relationship between these measures and the stimulus parameters. The results of these experiments would aid in determining the role of discharge pattern in information processing by the auditory system.